Rusty was taken to the zoo's animal hospital and received a rabies booster shot as a precaution.

The distance he had covered puzzled keepers, who reviewed surveillance video to make sure nobody removed him from the enclosure. Ultimately, they determined it wasn't foul play -- it was heavy rain, which caused branches to bend closer to the edge of Rusty's enclosure, providing a means of escape.

And the reason? Hey, a red panda's gotta eat. Staffers believe he would have been attracted to nearby bamboo and wanted a treat.

Rusty was the first animal to go missing from the zoo in recent memory.

"But he is a young male, he is a 1-year-old male, and we all know that young males like to test boundaries," said National Zoo Senior Curator Dr. Brandie Smith last year.

Oh, those teenagers, escaping their zoo enclosures and heading to a neighborhood known for its party atmosphere on the weekends.

He and his lady love, Shama, have new digs at the Smithsonian's Conservation Biology Institute in Front Royal, Virginia, where they moved in hopes of expanding their family.

They relocated in January because keepers were worried that the increase in zoo visitors intent on seeing one of those other pandas -- namely, giant panda cub Bao Bao -- could disturb the potential parents.